Recently, due to deterioration of environmental factors, risk of air pollution and water pollution in living space is increasing. To cope with such risk, fluid purification apparatuses such as air cleaners, water purifiers, etc. have been proposed in related industries.
As an example, water purifiers are classified into a natural filtration type, a direct-connection filtration type, an ion-exchange resin type, a distillation type, a reverse osmosis type, etc. according to a purification method. Recently, methods of directly sterilizing target water using ultraviolet light have been proposed.
In most conventional methods using ultraviolet light, target water to be treated is contained in a container having a predetermined volume. An ultraviolet light source is thereafter immersed in the target water and then turned on to sterilize the water. However, such an immersion type sterilization method is problematic in that it takes a relatively long time to sterilize target water by radiating ultraviolet light into the water, and it is difficult to uniformly sterilize the entirety of water in the container. A representative conventional technique using such an immersion type sterilization method was introduced in Korean Patent Unexamined Publication No. 2012-0134809.